The proposed studies examine the morphology and metabolism of adipose tissue from nonobese and obese patients and correlate the in vitro tissue findings with various metabolic functions of the whole individual as measured in vivo. Morphologic studies of the adipose tissue include determination of adipose cell size and number in individuals of widely different body weight. Metabolic studies in these adipose tissues investigate the glucose and lipid metabolism, and the hormone (insulin, epinephrine) responsiveness of adipose tissue as a function of adipose cell size, dietary composition and antecedent changes in body weight. Specific emphasis is placed on dissociating the effects of these three factors on the metabolic character of the adipose tissue and the overall metabolism of the individual as measured in the forearm tissues and assayed in the plasma.